Sympathetic and parasympathetic nerves have opposite effects Two stage neural

Sympathetic and parasympathetic nerves ( have opposite effects) ▪ Two-stage neural paths: neuron exiting the CNS synapses on a second-stage neuron before the target organ ▪ Autonomic Nervous System ○ Peripheral Nervous System (PNS) General Layout of the Nervous System Chapter 3: The Anatomy of the Nervous System Wednesday, January 13, 2016 1:10 PM Midterm Page 19

Major Divisions of the Nervous System This is a great diagram for you to practice you knowledge concerning the organization of nervous system. • Notice that the nervous system is a system of twos. • Meninges, Ventricles, and Cerebrospinal Fluids (CSF) Dura mater: tough outer membrane ○ Immediately inside the dura matter ▪ Underneath is subarachnoid space - contains many large blood vessels and cerebrospinal fluid ▪ Archnoid membrane: web-like ○ Pia mater: adheres to CNS surface ○ The CNS is encased in bone and covered by three meninges • Meninges Midterm Page 20

The brain dose not have pain receptors. ○ Meninges have pain receptors - source of pain. ○ Brain goes from functionally weighing 1300g to approximately 50g. ○ With some missing you suffer from ragging headaches and experience stabbing pain ○ Fluid serves as a cushion • Buoyancy a. Protection b. Chemical Stability c. Clearing Waste d. Function • Cerebrospinal Fluid (CSF) Absorption of cerebrospinal fluid from the sub-archinoid space into a major sinus. ○ Buildup of fluid in the ventricles causing the walls of the ventricles, and thus the entire brain, to expand, producing a condition treated by draining the excess fluid from the ventricles • Hydrocephalus Ventricles Midterm Page 21

We don't want any blockage of the fluids that will cause increased pressure and you can die from this • are often measured for certain neurodegenerative diseases - CNS begins to waste away. ○ Empty spaces fill with fluid and become larger and larger. ○ Schizophrenia does this, which suggests that it might be a neurodegenerative Some think the cells are getting smaller thus there's still a debate. ○ Lateral Ventricles • i.e. recall L-Dopa is used as a precursor to dopamine to bypass BBB ▪ The blood -brain barrier (BB): tightly packed cells of blood vessel walls prevent the entry of many molecules ○ Some large molecules that are critical for normal brain function are actively transported through cerebral blood vessel walls. ○ Many CNS disorders are associated with impairment of the blood-brain barrier, which adds to the symptoms of the disorders ▪ Head trauma can disrupt the BBB and result transfer of protein and other foreign matter into the brain space. ○ Chemical Protection Protecting the Brain Skull ○ Meninges ○ Cerebrospinal fluid (CSF) ○ Physical Protection Specialized cells for the reception, conduction, and transmission of electrochemical signals ○ Many sizes and shapes ○ Neurons • Cells of the Nervous System: Anatomy of Neurons Different brain areas seem to be somewhat specialized and when we dissect those areas we see that there are defining features.